A system for monitoring a fire has been researched for a long period of time and includes, for example, a temperature detecting scheme, a smoke detecting scheme, a flame detecting scheme, and the like.
As the related art, Korean Patent Laid-Open Publication No. 10-2007-0119593 (Composite fire detector for the detection of smoke, flame, and heat) discloses a composite fire detector that uses a single fire detector integrated with a heat detector, a smoke detector, and a flame detector to simultaneously provide a smoke detecting function for preparing against spontaneous combustion and a flame detecting function for preparing against a fire. The composite fire detector has a low error rate for various fire situations and can detect a fire from the beginning.
However, the composite fire detector does not detect a fire well at the time of an initial fire in which a temperature or a smoke density of a position at which a detection sensor is installed is not high and cannot detect flame when flame is hidden by objects or a fire occurs at an isolated dead zone and thus, cannot detect a fire in the early stage.
As another related art, Korean Patent Laid-Open Publication No. 10-2009-0082800 (Fire detection system) discloses a fire detection system including various sensors and a signal processing unit to detect flame, smoke, and heat, thereby accurately detecting fire occurrence and to transmit the detected information, thereby reducing malfunction and non-operation.
However, the fire detection system can sense smoke or heat in the state in which a fire somewhat progresses and it is difficult to detect an initial fire occurring at a spot hidden by objects, an isolated spot, or a hidden dead zone.
As another related art, US Patent Laid-Open Publication No. 2006/0192670 (Multi-senor device and methods for fire detection) discloses a fire detector using a multi-sensor that uses a multi-sensor coupled with a smoke senor or a heat sensor while basically using an optical sensor to minimize a malfunction of a fire alarm.
However, it is also difficult for the fire detector using the multi-sensor to detect a fire occurring at a spot hidden by objects, an isolated spot, or a hidden dead zone.